Complexation to cadmium(II) of a tetradentate ligand resulting from the condensation of 2-pyridinecarbaldehyde with N-(2-aminoethyl)propane-1,3-diamine

Abstract

The reaction of 2-pyridinecarbaldehyde with N-(2-aminoethyl)propane-1,3- diamine in a 2 : 1 molar ratio under microwave irradiation gave 2-(2-(pyridin-2-yl)-tetrahydropyrimidin-1(2H)-yl)-N-(pyridin-2-ylmethylene) ethanamine (L) as a mixture with the isomer 3-(2-(pyridin-2-yl)imidazolidin-1- yl)-N-(pyridin-2-ylmethylene)propan-1-amine (L*). The molecules were characterized by elemental analyses and spectroscopic methods. Percentages of L and L* were evaluated through integration of selected 1H NMR signals. The cadmium iodide complex of L, [Cd(L)I2] H2O (1), was prepared and identified by elemental analysis, FT-IR, Raman, and 1H NMR spectroscopy, and single-crystal X-ray diffraction. In the crystal structure of 1 the cadmium atom with four coordinated nitrogen atoms and two iodide ions has a distorted octahedral geometry. A water molecule is also incorporated in the crystal network. Several hydrogen bonds including N-H O, C-H O, C-H I, and O-H I interactions are present in the crystal structure of 1. © 2013 Verlag der Zeitschrift für Naturforschung, Tübingen.